There are many occasions when the need for reliable communications along railroad by-ways is necessary for both routine maintenance and emergency services. Radios are commonly used by maintenance workers, however, radio communications are not always effective in environments where the limited range of radio signals is greatly affected, for example, within railway tunnels. Similarly, the use of radios by emergency services personnel, for example fire and medical, are problematic both in communications among such personnel at the scene of an emergency and with a remote command post. Additionally, the ability to deliver emergency voice communications to passengers stranded along a by-way, for example in a tunnel or on a bridge, has been extremely difficult absent an accessible public address system.
Many rail systems are powered by electricity, with trains connecting to a high voltage source of electricity either by overhead linkage and/or by means of a third rail. Dangerous and life threatening situations arise when passenger and railway personnel are exposed to these high voltage sources. Restoration of high voltage power must be performed manually at the scene. Rapid disconnection of third rail electrical power, for example, has typically been accomplished using manually controlled dual-lever pull stations located at intervals along a rail line. Open access of the dual-lever pull stations may also be subject to misuse by pranksters and corruption by vandals.
Call boxes are used to provide certain communications for various points along a railway line, particularly in tunnels and on bridges or at stations with central stations or intermediate receiving stations. Vandalism of such call boxes is a problem ranging from defacement or destruction to theft of the units. In addition, call boxes have also been subject to environmental abuse from ambient moisture and ambient particulate. To determine whether operation of a call box has been compromised, periodic field testing is required to ensure performance by maintenance personnel, who must then repair and/or replace the units in the field. Remote testing of the units has typically not been available, nor have the units been mounted such that they may quickly and easily be disconnected by maintenance personnel.
In some localities emergency services personnel have set up a system whereby special plug-in handsets are utilized with a call box to set up local party lines. For example, a fire department may use such a system to communicate and coordinate emergency crews in a crisis vicinity, such as a tunnel where radio communications might not be effective, as well as connecting with a command center. These specialized voice connections have for the most part not been incorporated into permanently installed call box stations.
Emergency call boxes have evolved in functionality and technology. For example, U.S. Pat. No. 4,176,254 discloses an emergency roadside telephone system whereby wireless methods of communications are utilized. The call box disclosed in this patent has a transmitter and receiver handset for voice communications and a plurality of emergency pushbuttons identifying various emergency services, for example, fire, ambulance, road service or operator. By depressing one of the emergency pushbuttons, the unit automatically dials a preprogrammed number for the requested service. However, this unit only permits wireless calls to be placed via a central station. The user must communicate with the handset using wireless communications which is not suitable where tunnel-type environments are involved. The unit is not vandal resistant, does not allow for sound activated communications by various emergency services, and lacks the ability to function as a public address system. Also, the unit does not allow for inter-unit communications, that is, users such as maintenance crews cannot utilize the call box of this patented device for communications to other call boxes along the wayside.
Another type of call box disclosed in U.S. Pat. No. 5,283,546, although directed to a vandal-resistant call box, has many limiting features, including the use of wireless communications, and the inability to communicate with anyone other than an emergency operator. This call box also lacks the functionality that would allow the user, for example, to communicate with other call boxes, or to place telephone calls to locations other than an emergency operator, and further fails to permit alternate voice activated communications. Public address functions and remote activation of the call box are also not considered.
An emergency communications call box must also be accessible to a user while not interfering with ambient traffic, for example vehicles or people. In a tunnel environment, space for mounting materials and equipment is severely limited, and clearance must be maintained so as not to interfere with the general use of the tunnel. Mounting surfaces may vary within tunnels and along waysides, requiring a call box and a mounting bracket that are adaptable to various angles, slopes and clearance limitations.
Accordingly, there exists a need for a wayside safety station that has multi-functionality, is easy to use, resistant to environmental abuse, vandalism and theft, can be remotely activated and tested, and can be quickly and easily replaced for repair or maintenance.
It is accordingly a primary object of the present invention to improve communications services along transportation corridors through a multifunctional communications safety station that, can be mounted and used in a tunnel environment, is resistant to vandalism, is not limited by the relatively short range of radio signals, and can deliver emergency and routine voice communications to a user.
Another object is to permit voice communications between a wayside communications safety station and other wayside communications safety stations, and between a wayside communications safety station and other telephone terminals.
A further object is to provide an accessible pushbutton on the safety station that allows a user to quickly and safely disconnect direct current traction power used for powering electric transportation vehicles.
Still another advantage is the ability of the station to function as a public address system, permitting passengers and others within the vicinity of the safety station to receive instructions from personnel responding to an emergency or other situation requiring public address.
Yet another object is the ability to make non-emergency public address announcements affecting listeners in hearing range.
Still another object is the ability of a safety station to be remotely activated to enable a caller to the safety station to monitor ambient sounds.
Another object is to facilitate emergency party line voice communications through the safety station.
A further object is to provide a mounting bracket that is adaptable to be attached to mounting surfaces of varying slope, allowing the safety station to be mounted as close to the mounting surface as possible.
Still another object is a safety station that can be quickly and easily attached to or removed from a mounting bracket, making repair and replacement cost effective.
Still another object is integration of emergency call functions with routine communications functions among maintenance workers, emergency power disconnects, telephone functions, and sound powered communications into one unit.
Still another object is to permit an operator at a central station to send diagnostic signals to the safety station to test and verify the proper working order of the unit, thereby facilitating maintenance and minimizing down time of the unit.
An additional object of the invention is to minimize external access to moving parts, through fabrication of a safety station having improved strength and resistance of components exposed to the ambient rugged and hostile environment.